Born in Bavaria in 1845, Isidor Straus came to the United States at the age of 9, residing first in Georgia and then in New York City. Together with his brother Nathan, Isidor started to sell glassware and china in R. H. Macy's in 1873. By 1896, the enterprise was so successful that the Strauses purchased the entire store, helping to build what is now the largest store chain in the world.
Isidor Straus was a trusted advisor to President Grover Cleveland, and he was elected as a Democrat to the fifty-third Congress to fill the vacancy caused by the resignation of Ashbel P. Fitch, and served from January 30, 1894, to March 3, 1895. He did not run for reelection in 1894 to the Fifty-fourth Congress.
Straus resumed the mercantile business in New York City and served as a member of the New York and New Jersey Bridge Commission. He was also a founder of an endowment fund for the Jewish Theological Seminary.
Straus sailed on the maiden voyage of the Titanic. When the ship was sinking on April 15, 1912, because of his age (67), Isidor was told that he would be allowed to depart with the women and children. But he firmly refused any special treatment, saying he would enter a lifeboat only with the other men. He urged his wife Ida to board a lifeboat, but she also declined, reportedly saying, "We have been living together for many years, and where you go, I go." Over 40,000 people attended the couple's memorial service, and their story was told in a Yiddish song by Solomon Smulewitz.
The body was subsequently recovered and interred in the family vault in Beth-El Cemetery, Fresh Pond Road, Brooklyn, N.Y.